Machine for coaxial cable insulation



-c. RAABE MACHINE FOR COAXIAL CABLE INSULATION Aug. 8, 1944.

Filed Oct. 15, 1942 3 Sheets-Sheet 1 faae.

v t'drrney Q 'Aug.-8, 1944. c, RAABE 2,355,238

MACHINE FOR COAXIAL CABLE INSULATION Filed 001:. 15, 1942 3 Sheets-Sheet: 2

' Aug. 8; 1944.

- c. A. RAABE 2,355,238 MACHINE FOR COAXIAL CABLE INSULATION Filed Oct. 15, 1942 5 Sheets-Sheet 3 Patented Aug. 8, 1944 2,355,238 MACHINE FOR COA XIAL CABLE INSULATION CarlA. Raabe, Chicago, 111.,

Application October 15, 1942, Serial No. 462,203

4 Claims.

The present invention is directed to a novel machine for facilitating the stringing of insulating beads on electrical conductor wires. .As is well known, insulation of this type is highly desirable for certain uses, particularly where substantial flexibility is required, or where the conductor wire must be bent to a relatively small radius. Bead type insulations on electrical conductor wires may be utilized in coaxial cables, wherein the inner conductor wire is encased in a series of abutting beads of insulating material and around which insulating beads is disposed, a tubular form of conductor element constituting the second electrical conductor. The thus assembled conductors are in turn encased in suitable insulation to constitute a cable. Conductor wires provided with bead type insulation are also widely used in other forms than coaxial cable, as is well understood in the art. Heretofore, in making up substantial lengths of electrical conductor wire with insulatedbeads thereon, it has usually been found relatively expensive and time consuming. One of the common methods heretofore employed in stringing insulated beads on conductor wires, consisted in arranging the length of theconductor wire.

. treme opposite end of the wire. This process of shifting such accumulations of beads along the wire is repeated continuously until the entire length of the wire is covered by the insulating beads. i

The apparatus heretofore employed in the making up of conductor wire of this type requires considerable floor space, and frequently due to the size wire used necessitates limiting the lengthof the respective sections of the wire arranged intier form so as to avoid imposing unduestrain' on. the. wire which may result in causing break-' age thereof. By virtue of such apparatus-thelength. of. the wireto be covered by the insulat ing. heads; is necessarily limited, and it has not been found convenient and practical to stringv the. beads over a wire of more than five or six hundred feet inlength. a

The machine constituting the present invention, now for the first time makes it possible to conveniently and practically string insulating beads on; electrical conductor wires of several 'thousand f eet in length. For certain uses it is well recognized that it is highlydesirable that such insulating type of conductor wires be formed as a continuous or single cable, and up to the present time it has not been possible to make up such wires of a desired and necessary length.

relatively long lengths of conductor wires.

One of the objects of the present invention is to provide a novel machine of the character indicated which is constructed and arranged for facilitating the stringing of insulating beads on Another object is to provide an improved machin of the character indicated which is relatively simple, compact and which occupies a minimum amount of floor space.

A further object is to provide an improved machine of the character indicated by virtue of which it is possible to obtain rapid stringing of insulating beads on long lengths of electrical conductor wires in a manner which results in a substantial saving in both labor and cost of manufacture.

-Still another object of this invention is to provide a novel machine for and an improved method of stringing insulating beads on relatively long lengths of electrical conductor wires.

Other objects and advantages of this invention will be apparent from the following description taken in connection with the accompanying drawings in which: 7 V V Fig. 1 is a diagrammatic View of my novel machine,,embodying-the present invention, shown in side elevation. V

- Fig. 2 is a diagrammaticplan viewof the machine.. V I I Fig. 3 is a transverse vertical section through the machine, taken as indicated Fig. 2. i l a Fig. 4 is a view of afragmentary portion of a conductor 'wire covered'with insulating beads, with some of the beads being shown in section.

Fig.5 is a transverse section through the insulatedconductor wire,-taken at line 5-5 of Fig. 4.

Fig. 6 is a perspective viewof an auxiliary guide adapted to be used in conjunction with themachine when relatively small size conductor wire is employed so as toreduce the strain imposed upon the wire duringthe process of moving a multiplicity of beads alon the wire. Y

In the drawings, Ighave shown merely for purpose of illustration, my novel machine as itmay be used-in the process ;.of stringing beads on a one conductor wire. ;It will be understood that due to the construction of themachine; as will hereinafter be described, it is possible that two at line 3- 3 of reducing mechanism indicated at 25;

separate lengths of conductor wire may be simultaneously operated upon in stringing insulating beads thereon.

The machine includes a convenient height work bench or table l0, connected at opposite ends to suitable framing II and [2, in which there is journal supported relatively large size drums indicated atv I 4 and 15 respectively, mounted for rotation about horizontal axes. These drums-are provided at opposite ends with suitable stub shafts Ida and I5a, journalled in suitable bearings l6 carried by the frames H and i2. As a typical example of a practical sized drum to be employed it may be understood that four face of approximately five feet. The opposite ends of the respective drums are provided with end flanges H, which serve to guide the wire onto and off of the drums and for confining it in position thereon as well as serving as a convenient means for anchorageof the ends of the conductor Wires. Corresponding stub shafts Ma and l5-a, at one side of the machine, are provided with similar sprocket wheels Hi around which is trained a chain ZO by virtue of which the two-drums are interconnected so as to be simultaneously driven at the same speed'and in the same direction.

The stub shaft Ma, carrying the sprocket wheel I9, is also provided with a larger sprocket wheel 22 around which is trained a chain 23 which is also trained around the driving sprocket wheel 24 which is directly connected to a speed The speed reducing mechanism may be understood to be of a variable speed type, having appropriate manually operated controls (not shown), for varying the drums as illustrated are approximately the speed of rotation of the-sprocket wheel 24' and by which the speed of rotationof the two drums M and i5 may be correspondingly varied.

The in-put end of the speed reducer'25 includes a driven Wheel 21 which is driven by means of a belt 28 from the pulley wheel 29 on the end of the motor shaft of the motor indicated at 39. I v

In the use of the machine constituting the present invention it is desirable that the drums Hi and i5 be rotated intermittently uriderthe direct control of the operator and forthis purpose a two way switch indicated at 35 is employed. It is to be understood that the switch 35, which is represented diagrammatically, is connected by suitable conductor wir'es' (not shown) to the motor so that the motor may be" about eight or ten feet, which is adapted to be disposed freely upon the surface of the work bench ill. paratory to winding around drum [4 is first secured to one of the flanges H of thedrum M; in any suitable manner, such as by anchoring the end of the wire as indicated-at- 3B-,- through an aperture in the adjacentflangei At the end of the work benc-h e r table M; im-'- mediately. adjacent the drum-15 is disposed a combination guide and traversemechanism for controlling the conductor wire 40 in paying onto= andofi of the the drum l5, as will be herein- The'opposite end of the wire, pre-' feet in external diameter, and having a- I by the operator.

after described. The traverse includes a screw 42, formed with a pair of oppositely extending threads as is well understood in the art, said screw extending horizontally in closed spaced relation to the top of the table l0 and having its opposite ends journalled in bearings 43. One end of the screw projects beyond the end of one of the bearings and is provided with a sprocket wheel around which is trained a chain 45, passing downwardly through an opening in the table top and trained around a sprocket 48, associated with a speed reducing mechanism 49, directly connected to an electric motor indicated at 55. As will be hereinafter described, the

traverse mechanism is only intermittently operated and, hence, a convenient hand switch indicated at 52 for controlling the motor 50, is disposed at one end of the table for manipulation Mounted on the screw 42 is an upwardly extending carrier 55, the lower end of which is formed with suitable internal projections or threads for meshing with the threads of the screw 42, said projections being subject to the control of a manually adjustable handle 51, which as shown in Fig. 3 of the drawings is in neutral position. Said handle may be swung to one side or the other for causing the internal projections of the carrier to engage respectively in either of the two sets of threads of the screw 42. Therefore, since the screw 42 will be caused to rotate in only one direction, it is possible by the adjustment of the handle 51 to cause the traverse 55 to move toward either one end or the other end of the screw as may be desired. The upper end of the traverse is guided for transverse movement in a slot 58a formed in a bar 58 connected to the upper ends of a pair of uprights 59' carried onan adjacent end of the table Ill.

Connected to the upper portion of the traverse 55 is a plate 60 provided with a multiplicity of upwardly open slots 6 i. For convenience in use of the machine" it may be understood that said slots are formed in two series of various widths for accommodating different sizes of electrical conductor wires, and the slots of the respective series are preferably formed in multiples of two of the same size sothat if desired two separate lengths of conductor wire of the same size may be simultaneously operated upon.

It is to be understood that the insulating beads employed may be of various size and contour, and as represented in Fig. 4 said beads are of substantially cylindrical form, rounded at one end, as indicated at B6, and are each provided with a relatively large generally frusto-conical cavityfil, terminating in a large opening at the other end. The closed end of each of the beads is provided with an axial opening 58, substan- 40 between adjacent beads-. Thuscomp'lete insulation for the conductor wire 4i} isIma-intained,

at all times.

As-above stated the machine as illustratedfis" capable of use for simultaneously stringing beads on two separate lengths of conductor wire, in which case an operator would stand on opposite sides of the table ID; with therespective lengths of the conductor wires wrappedaround opposite end portions of the drum I4, leaving a terminal portion of convenient length, say of feet of each wire, free to rest upon the table III. .The operator or operatorsthen string on to the free portion of the conductor wires'a sufiicient. length ofthe insulated bead 55 until said portion thereof becomes filled and the beads abut against the surfacelof the drum I4.. When such'a portion of the conductor wire is filled with beads the. operators then tend to force the beads along the adjacent portion of the wires constitutingthe next adjacent convolution wrapped around the drum I4, and the extreme free end of the wires is then seated in appropriate slots 6| of the traverse plate 60, and the terminal end of each wire is fastened in the adjacent one of the spring pressed hand clamps indicated at 10, or both wires may be fastened in one of said clamps, mounted on the inner face of the end flanges I1 of the drum I5. 1 i

The control 5! of the traverse is adjusted and the respective switches and 52 are then manipulated to close the circuits and drive the moloicomes covered with the beads.

ent that during the continuous operation of.

tional strain imp s on the Wires by the beads tors 30 and 50, which cause the drums I4 and I5 to rotate in the same clockwise direction as indicated by the arrows in Fig. 1. The beads 65 on the conductor wires abut against the plate 60, While the wire passes therethrough and is paid onto the drum I5. The machine continues to operate until substantially the entire lengths of the conductor wires are unwrapped from the drum I4 and are wrapped on the drum I5, during which time the traverse 55, has been caused to move along the screw 42, to properly space the convolutions of the'wires across the face of the drum I5. As the fixed ends 38 of the conductor wires 40 are approached, the switches 35 and 52 are opened to arrest the motors 30 and 50. To insure'no appreciable over-running of the drums, the operator'may manipulate the foot brake indicated at I5, having afoot treadle I6 which retards and brakes the speed of the drum I5, and which through, the drive connection made bythe chain 20, simultaneously retards or brakes the speed of the drum I4. The beads 65, due to abutment against theplate 6|], will be. disposed on sections of the, wires, adjacent the other extreme or fixed end portions thereof. The operators then push the section of beads along the wires until they cover the extreme end portions thereof. The switch- 35 isthen reversed and control handle 51 of the traverse is,rev ersed and switch 52 closed, to complete circuits to the motors 3i] and 50. The drums I4 and I5 now rotate in counterclockwise direction and the conductor wires are wound off of drum I5 and wrapped around drum I4 until substantially the entire lengths of the wires are wound around the drum I4, with the exception of a terminal portion of 8 or 10 feet in length, which is again left free upon the table II) for repeating the bead stringing operation. During such unwinding operation the traverse 55 serves as a guide for the wires as they are paid 01f of the drum I5. It is to be understood, of course, that when the drum I4 has substantially all the wire paid thereon, the switches 35 and 52 are opened, and the foot brake I5 operated so that the drums may be arrested at a proper time to permit release of the terminal ends of the wires from the clamps The terminal portions of the wires are again covered with insulating beads and the machine is again operated as above described to cause the new sections of beads to become lodged in abutting relation against the previously assembled section of beads. ti 1 eventually the entire length of the wires be- It will be apparstringing and assembling of the beads the amount of, wire necessary to be unwound fromthe drum I4 ,onto the drum I45 gradually diminishes, it. ybeing necessary only to unwind the portion of the wire which has not been covered by the beads.

..The purpose of the variable speed reducing mechanism .25 is to control the speed of rotation of the drums I4 and I5. This is important when stringing beads on conductor. wires of different sizes. When relatively fine or small size wire is employed, there is a substantial possibility of breakage and, hence, undue strain on the wire must be reduced to a minimum. In this connection it is sometimes desirable to relieve the fricdue to their abutment against the traverse plate 60 and for this purpose the operator may grasp by his hand an intermediate section of the beads which are arrested by abutment with the plate 60, during the period-that the Wire is passing therethrough and is being paid onto the drum I5.

If desired when relatively fine wire is employed an auxiliary guide and abutment as represented .in Fig. 6 of the drawings may be utilized. This auxiliary guide is in the form of an inverted U- shaped frame 8!], provided at one of the upper corners wiht a block 8|, from which extends a pair of relatively closely spaced apart horizontally extending rods 82, it being understood that the space between the rods being sufiicient to accommodate relatively small size wires. The legs of the frame may be fitted in sockets indicated at 83, formed in the top of the table II], and the 4 wires may be passed into the slot formed by the Thus the frictional strain on the beads during the time that the wire is .being passed therethrough, in the passing of the wire onto the drum I5, is greatly relieved.

It will be apparent that my novel machine I- greatly facilitates the operation of stringing of insulating beads on long lengths of conductor wires. Such a machine now makes it possible to string beads on Wires of several thousands of feet in length, the length of the wires of course being limited only to the extent of convenient wrapping around and accommodation on the drums I4 and I5. When the wires have been completely covered by the insulating beads they may be conveniently removed from the drums and wrapped on to a flanged roll of smaller size for convenient use in connection with apparatus for the assembly in either coaxial cable or multiconductor cable as conditions may require.

Although I have shown and described a preferred embodiment of my invention, manifestly it-is capable of modification and rearrangement of constructional features without departing from the spirit and scope thereof. I do not, therefore, wish to be understood as limiting this invention to the precise form herein disclosed,

Thus operation is repeated unexcept as I may be so limited by the appended.

claims.

I claim as my invention? lpIn a machine of the character described; the combination of an elongated work table of convenient height, a pair of rotatable drums mounted onhorizontal axes, transversely of the direction of length of the table, adjacent opposite ends of the table, one of said drums being adapted to have a substantial length ofconductor wire wound thereon with a short'end portion o-i said wire disposed freely on the table for stringing of insulated beads thereon in abutting relation, the other drum being adapted, after said portion of the wire is covered with beads, to have the terminal end of the wire connected thereto, manually controlled, reversible power driven mechanism operably connected to both said drums for simultaneously rotating them in the same directions, said drums during one direction of rotation causing the wire to be paid'oif said one drum and onto said other drum,

and abutment means for restraining movement ofsaid section of beads during winding of the Wire onto said other drum, together with manually operated brakingmeans for directly retarding rotation of said other drum andthrough said mechanism retarding rotation of said one drum when the driving of said power driven mechanism is interrupted.

2. In a -machine of the character described, the combination of an elongated Work table of convenient height, a pair of rotatable drums mounted on horizontal axes, transversely of the direction of length of the table, adjacent opposite ends of the table, one of said drums being adaptedto have a substantial length of conductor'wire wound thereon with a short end portion of said wire disposed freely on the table for stringing of insulated beads thereon in abuttin relation, the other drum being adapted, after said portion of the wire is covered with beads, to have the terminal end of the Wire connected thereto, manually controlled, reversible power driven mechanism operably connected to both said drums for simultaneously rotating them in the same direction, said drums during one direction of rotation causing the Wire to be paid off said one drum and onto said other drum, and abutment means for restraining movement of said section of beads during windingof the wire onto said other drum, together with foot operated braking mechanism operably associated with said other drum for retarding rotation of said other drum and said one drum throughisaid power driven mechanism.

3. In a machine of the character described, the combination of an elongated work, table of convenient height, a pair of rotatable drums mounted on horizontal axes, transversely of the direction of'lengthiof the table, adjacent oppositeendsof the table, one of said drums' being adapted to have a substantial length of conductor wire wound thereon with a short end portion of said wire disposed freely on the table for stringing of insulated beadsthereon in abutting relation, the other drum being adapted, after said portion of the wire is covered with beads, to have the" terminal end of the wire connected thereto; power driven mechanism, adapted to be actuated under control of the operator, for rotating said other drum for causing the wire to be paid 01f of .said'one drum and onto said other drum, abutment means adapted for restraining.-

movement of said section of beadsduring winding of the wire onto said other drum, wherebyto lodge said section of beads adjacent theopposite end portion of the Wire, said abutment means being mounted on the table adjacent said other drum and serving as a guide for feedingsaid wire onto said other drum, and power driven means including operating connections for mov- .ing said abutment means transversely of the face of the said other drum for transaxiallyspacing the convolutions of wire being wound thereon.

4. In a machine of the character described,

the combination of an elongated work'table of w convenient height, a pair of rotatable drums mounted on horizontal axes, transversely of the direction of length of the table, adjacent opposite endsof the table, one of said drums being ,adapted to have a substantial length of conductor wire wound thereon with a short end portion of said wire disposed freelyv on the table forstringing of insulated beads thereon in abutting relation, the other drum being adapted, after said portion of the wire is covered with beads, to have the terminal end of the wire connected thereto, manually controlled, reversible powerdriven mechanism operably connected to said drums for simultaneously rotating them in the same directions, said drums during one direction of rotation causing. the wire to be paid offsaid one drum and onto said other drum, abutment means for restraining movement of said section of beads" during winding of the Wire onto said other drum,.said abutment means being mounted" on the table adjacent said other drum and serving as a guide for feeding said wire onto said other drum, and power driven means including operating connections for moving said abutment means transversely of the face of the said other drum for transaxially spacing the convolutions of wire being wound thereon.

CARL A; RAABE. 

